JP3939664B2 - Purification method and system for lakes and the like - Google Patents

Description

前記のリンなど除去のための第一浄化工程に用いられる超電導磁気分離装置５においては、設置スペ−スは処理水量５０００m３/日（人口約２万人分の水道給水量に相当）の装置の場合、設置スペ−スは約３００m^２で、 リン除去率は８５%以上が得られる。一方、第二浄化工程である植生浄化設備７において、窒素の除去を行なう場合、水量５０００m３/日を浄化するために必要な植生面積は、ヨシの場合、原水中の窒素濃度を１０PPMとすると、約５０万m^２のヨシ原で６７%の窒素が除去できる計算である。この必要面積は第一のリンの浄化工程に比べて、桁違いの広大なスペ−スになる。
【００５８】
しかし、これだけの植生面積を確保できなくても、富栄養塩の一方のリンが除去されたことによって、成長、繁殖ができなくなっていた植物の成長にとってより好ましい環境に整えられるので、水中の窒素及び残存リンを栄養源として成長できるようになる。それは、アオコなどの藻類は栄養塩、光、水温、炭酸ガス、水の循環等の一定の条件が一つでも欠けると繁殖が抑制されることがわかってきたからである。
【００５９】
したがって、現実的には植生７の設置スペ−スの制約から、リン除去装置の処理水の全量を対象に窒素を分離除去することは難しいが、超電導式磁気分離装置５の処理水の一部分について植生７で浄化しても目的の一部を達成することが可能である。このため、第一浄化工程で汚濁物質を分離除去された処理水の大部分については第二浄化工程をバイパスさせることでもよい。図１の俯瞰図はそのような例を示し、第二浄化工程を実施する第二の浄水領域６ｂの周囲を取り囲むように仕切り体１４を配置し、第二浄化工程の第二の浄水領域６ｂの沖側を迂回して貯留水が流下できるようにしたものである。
【００６０】
ここで、このバイパス水路第一の浄水領域６ａと植生帯第二の浄水領域６ｂについては水が交じり合っても、問題はなく、湖沼２から仕切った浄化領域６を介して伝播してくる水流や、波浪を防げる程度の仕切り体１４で十分である。また、浄化領域６内においては、その外の湖沼水との仕切り体１０によって水が混じりあうことがある程度抑えることができれば十分である。逆に仕切り体１０に少量の水の出入りを許容することにより、河川流や吹送流による仕切り体１０への外力が緩和され、仕切り体１０の流出を防止することができる。
【００６１】
また、例えば、水道水源の場合、夜間の取水量が減った場合などにおいても、超電導式磁気分離装置５の運転を継続して行なえば、浄化領域６内の貯留水は増加して、その外部の湖沼２へ流出し、湖沼の希釈水として浄化にも寄与できる。さらには、河川水の浄化だけでなく、湖内の底泥の浚渫除去も同時に実施すると、より効果的である。富栄養湖沼は底層付近は貧酸素状態になり、堆積したリンや窒素などが底泥から溶出してさらに栄養塩負荷に加わるからである。
【００６２】
その他、第一浄化工程では凝集沈殿ろ過方法なども適用が可能である。この方法においてはリン酸塩や浮遊固形物などを除去できるからである。
【００６３】
本実施形態によれば、湖沼などの閉鎖性水域２に河川などから流入する水の一部を取水し、この水を物理化学的に処理して主にリンを除去する第一の浄化工程と、閉鎖性水域２を深さ方向に仕切って形成した浄化領域６に第一の浄化工程で処理された処理水を導入し、この処理水を浄化領域６内で生物処理して主に窒素を除去する第二の浄化工程とからなるので、湖沼などの浄化領域６でのリンや窒素などの汚染物質による富栄養化を抑制して良質利水のための水源を得るとともに浄化領域６の親水性および本来の生態系を回復させることができる。
【００６４】
さらに、超電導式磁気分離装置５を用いて物理化学的処理しているので、高速高効率なリン分離除去ができ、これによって水質浄化における大幅な省スペース化および省エネルギー化を図ることができる。
【００６５】
さらに、植生を用いた生物処理を行なっているので、閉鎖性領域２内の特定部分を構成する浄化領域６の景観を良好にしつつ、本来の生態系を回復させることができる。
【００６６】
また、湖沼などの閉鎖性水域２に河川などから流入する水の一部を取水し、この水を超電導式磁気分離処理して主にリンを除去する第一の浄化工程と、閉鎖性水域２を深さ方向に仕切って形成した第一の浄化領域６ａおよび第二の浄化領域６ｂに第一の浄化工程で処理された処理水を分流してそれぞれに導入し、第二の浄化領域６ｂに導入した処理水をその第二の浄化領域６ｂ内で生物処理して主に窒素を除去する第二の浄化工程とからなるので、比較的貯留水量の大きな閉鎖性水域６の水質改善をより効果的にまた確実に遂行することができる。
【００６７】
さらに、第二の浄化領域６ｂに隣接してこれを取り囲むように第一の浄化領域６ａを設けているので、第一および第二浄化領域６ａ、６ｂ内の処理水が流出入して混合することがあっても処理水同士の混合であり、第一の浄化領域６ａが汚染されることなく、しかも第二の浄化領域６ｂにおける所定の浄化性能を確保することができる。
【００６８】
【発明の効果】
本発明によれば、設備コスト、設置スペースおよび駆動エネルギーの最小化を図りつつ、湖沼などの浄化領域でのリンや窒素などの汚染物質による富栄養化を抑制することができる湖沼などの浄化方法及びその浄化システムを得ることができる。
【００６９】
また、本発明によれば、比較的貯留水量の大きな閉鎖性水域の水質改善をより効果的にまた確実に遂行することができる湖沼などの浄化方法及びその浄化システムを得ることができる。
【図面の簡単な説明】
【図１】本発明の一実施例を示す湖沼などの浄化システムを適用した周辺部分の平面図である。
【図２】図１のＡ−Ａ断面図である。
【図３】図２と異なる適用例の図１のＡ−Ａ断面相当図である。
【図４】図１の浄化システムにおける仕切り体の一部分を示す側面図である。
【図５】図１の浄化システムにおける超電導式磁気分離装置の磁気分離部の構成図である。
【図６】図５の超電導式磁気分離装置の磁気分離メディアを示す断面図である。
【図７】図１の浄化システムにおける超電導式磁気分離装置のシステム構成を示したフロー図である。
【符号の説明】
１…流入河川、１ａ…河川水取水口、２…閉鎖性水域（湖沼など）、３…湖岸、４…流出河川、４ａ…越流せき、５…超電導式磁気分離装置（物理化学的処理設備）、５ａ…第一処理水放出口、６…浄化領域、６ａ…第一の浄化領域、６ｂ…第二の浄化領域、７…植生、８…第一浄化工程水域、９…利水取水口、１０…第一の仕切り体、１１…浮き島、１２…浮き島用フロート、１３…浮島用土壌、１４…第二の仕切り体、１５…浮島用アンカー、１６…浮島用水位調節連通管、２０…仕切り板、２１…鎖、２２…重錘、２３…浮き部材、３０…生物処理設備。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a purification method and a purification system for lakes and the like, and purification technology for closed water areas such as eutrophied lakes, dam lakes, and harbors, in particular, closed water areas for tap water sources or landscapes for sightseeing, recreational use. The present invention relates to a purification technique for hydrophilic water areas.
[0002]
[Prior art]
In recent years, in the closed water areas such as lakes and marshes, which are water sources for water supply, the inflow of substances that cause eutrophication such as nitrogen and phosphorus has increased, and a eutrophication phenomenon has progressed in which algae are produced in large quantities and water quality deteriorates. Yes. Therefore, purification facilities using various technologies to purify the water area by suppressing eutrophication in closed water areas such as lakes and dam lakes as water sources or hydrophilic water areas are strengthened. I came.
[0003]
A number of technologies for purifying such closed waters have been proposed, but if these are classified, chemicals can be removed by mechanical removal of pollutants, technology by activating microorganisms, chemicals, etc. For example, a technology for processing in a closed manner, and a technology for processing by circulating a part of water in a closed water area.
[0004]
As one of the prior arts, for example, there is a water treatment method and apparatus disclosed in Patent Document 1. This Patent Document 1 discloses a water treatment method and apparatus for eutrophication in a closed water area, a treatment process and a treatment apparatus for removing algae generated along with eutrophication, and treatment with anaerobic microorganisms. Described is a water treatment method and apparatus comprising a treatment process and a treatment apparatus, a treatment process and a treatment apparatus for treating with an aerobic microorganism, and a treatment process and a treatment apparatus for removing phosphorus remaining by chemical treatment. Yes.
[0005]
Moreover, there exists a purification apparatus of the polluted water disclosed by patent document 2 as another prior art. In this Patent Document 2, a bubble recovery use frame with a float in which a plurality of concave cross-section ridges opened at the top are arranged at appropriate intervals on the inner water surface of a catamaran type carrier, It is connected to the draft state where the side edge is slightly above the surface of the water. A device for purifying polluted water is described which is provided to provide recovery means, remove suspended substances in water in closed water areas such as main lakes and seas, and purify water in the water areas.
[0006]
Furthermore, there exists a pond water purification equipment disclosed by patent document 3 as another prior art. This prior art is a pond water purification facility in a reservoir, irrigation reservoir, etc., in which a strainer and a water purification device are arranged on one side of the pond, and a hydrophilic zone in which gravel, sand, etc. are laid on the other side. A pond water purification facility is described in which a pond water that has been partitioned and purified by a water purification device is guided by a conduit to a hydrophilic zone through a man-made waterfall, and a water flow generator that generates a water flow toward the hydrophilic zone side strainer is placed in place. ing.
[0007]
[Patent Document 1]
JP-A-2-95498
[Patent Document 2]
Japanese Patent Laid-Open No. 5-287
[Patent Document 3]
Japanese Patent Laid-Open No. 4-90898
[0008]
[Problems to be solved by the invention]
However, substances such as phosphorus and nitrogen that promote eutrophication in closed water areas are mainly supplied from rivers that flow into the closed water areas. River water containing these substances flows into the closed water area and is diluted into the accumulated water there, so a large amount of water (water in the whole closed water area) must be treated with conventional purification methods and equipment. There wasn't. As a result, the above-described prior art has a problem that the production cost, installation space, drive energy, and the like of the purification equipment increase.
[0009]
An object of the present invention is to provide a purification method for lakes and the like that can suppress eutrophication due to contaminants such as phosphorus and nitrogen in a purification region such as lakes and marshes while minimizing facility costs, installation space and drive energy. And providing a purification system thereof.
[0010]
Another object of the present invention is to provide a purification method for lakes and the like and a purification system thereof that can more effectively and reliably perform water quality improvement in a closed water area with a relatively large amount of stored water. .
[0011]
[Means for Solving the Problems]
In order to achieve the above object, the purification method for lakes and marshes of the present invention mainly takes a part of water flowing from a river etc. into a closed water area such as a lake and treats this water physicochemically. A first purification step for removing phosphorus, and the treated water treated in the first purification step is introduced into a purification region formed by partitioning the closed water region in the depth direction, and the treated water is introduced into the purification region And a second purification step in which nitrogen is mainly removed by biological treatment.
[0012]
In order to achieve the other object described above, the purification method for lakes and the like of the present invention mainly takes a part of water flowing from a river or the like into a closed water area such as a lake and performs superconducting magnetic separation treatment on the water. The first purification step for removing phosphorus and the first purification region and the second purification region formed by partitioning the closed water region in the depth direction are treated water treated in the first purification step. It consists of a second purification step in which the treated water introduced into the second purification region is diverted and biologically treated in the purification region to mainly remove nitrogen.
[0013]
The other means of the present invention will be clarified from the following description.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a purification method and a purification system for lakes and the like according to an embodiment of the present invention will be described with reference to FIGS. 1 to 7.
[0015]
FIG. 1 is an overhead view of a purification target lake including a river flowing into the eutrophication lake as seen from above.
[0016]
In closed water areas 2 such as lakes, dam lakes, and harbors, a large amount of domestic wastewater and rainwater containing eutrophic substances such as phosphorus and nitrogen flows through the inflowing river 1. If appropriate measures against inflow load are not taken, eutrophic substances that flow into the closed water area 2 stay in the closed water area 2 and partly flow out from the outflow river 4, but most of the eutrophic substances are in the closed water area. 2 is accumulated. An overflow basin 4 a is provided in a portion of the outflow river 4 close to the closed water area 2.
[0017]
As a result, eutrophication of the water in the closed water area 2 proceeds, a large amount of algae are generated, the water quality deteriorates and the transparency is lowered, and the landscape is damaged. Such eutrophication will also significantly change the ecosystem. That is, there is a risk that the number of solids such as aquatic plants and insects growing in the closed water area 2, and fish and mammals depending on them may be reduced or extinct. Moreover, in the water supply which uses the said closed water area 2 as a water source, when using it as a water source of a water supply etc., the load increase of purified water supply equipment and the fall of supplied water quality (for example, musty odor etc.) will be caused.
[0018]
Therefore, in order to prevent eutrophication of the closed water area 2, it is necessary to separate and remove phosphorus, nitrogen components, suspended solids, and the like of the eutrophic substances contained in the river water flowing into the closed water area 2. . However, in general, the amount of inflow water from rivers varies greatly depending on the season, so it is difficult to purify the entire amount of inflow water from the viewpoint of economy. Moreover, the purification method differs between phosphorus and nitrogen. Nitrogen, in particular, needs to use the biological absorption action, and has a feature that it is difficult to remove at high speed compared to phosphorus, which can be removed by physicochemical in addition to the biological absorption action.
[0019]
For this reason, in designing an efficient purification method and system, how to set the elements of the amount of purified water and the removal rate of phosphorus and nitrogen minimizes construction costs and running costs, and maximizes the purification effect. We examined whether it could be limited.
[0020]
As a result, the following was found to be particularly effective. When the closed water area 2 is mainly used as a water source for water supply or agricultural water, the amount of water commensurate with the amount of water used is purified. Then, water in a state of high eutrophication substance concentration (that is, water in the inflowing river 1 or water immediately after flowing into the closed water area 2 from the inflowing river 1) is taken and purified. As a purification method, first, phosphorus and suspended solids that can be purified at high speed are removed by a physicochemical method, and then nitrogen is removed by biological treatment. Nitrogen removal provides a purification area in the closed water area 2 to prepare an environment in which plant growth and the natural purification ability inherent in the closed water area 2 can be exhibited.
[0021]
More specifically, in this embodiment, a river water intake 1a is installed near the mouth of the inflowing river 1 where the concentration of the eutrophic substance is the highest, and the necessary amount of water is taken from the river water intake 1a. Then, mainly phosphorus and suspended solids are purified through the superconducting magnetic separation device 5 constituting the physicochemical treatment facility. Details of this processing will be described later.
[0022]
The treated water treated by the superconducting magnetic separation device 5 is discharged and stored in the purification region 6 formed by partitioning the closed water area 2 with the first partition 10 through the first treated water discharge port 5a. In addition, if the 1st treated water discharge port 5a is said with respect to the purification | cleaning area | region 6, it will comprise the intake of treated water. The purification area 6 includes a plurality of purification areas 6a and 6b (in this embodiment, the first purification area 6a and the second water purification area 6b) formed by partitioning the purification area 6 with the second partition body 14. It is configured.
[0023]
The 2nd water purification area | region 6b is provided so that it may extend long from the inflow river 1 side to the outflow river 4 side along the lake shore 3. As shown in FIG. The first purification region 6a is provided adjacent to and surrounding the second purification region 6b. Therefore, the 1st water purification area | region 6a is extended long along the lake shore 3 via the 2nd water purification area | region 6b. The first treated water discharge port 5a is branched into a plurality, and the treated water is divided and discharged to the plurality of purification regions 6a and 6b. The 1st treated water discharge port 5a is installed so that it may be located in the edge part near the inflow river 1 side of the 1st water purification area | region 6a and the 2nd water purification area | region 6b.
[0024]
The water-use intake 9 is installed on the side of the reverse intake in the purification area 6 so that the treated water in the purification area 6 can be used as a water source such as tap water or agricultural water. In this embodiment, the water intake 9 is installed near the end of the first water purification area 6a on the side opposite to the water intake, and the treated water including both the first water purification area 6a and the second water purification area 6b is used as a water source. It can be used as.
[0025]
As shown in FIG. 2, the vegetation 7 is planted in the 2nd water purification area | region 6b. The vegetation 7 includes plants existing in the closed water area 2. A biological treatment facility 30 is constituted by the second partition 14 and the vegetation 7, and mainly nitrogen contained in the treated water flowing into the second water purification region 6 b is removed. The purified treated water flows out into the first purified water region 6a and is further taken out as utilization water from the water utilization inlet 9.
[0026]
In this way, phosphorus and nitrogen contained in the water of the inflowing river 1 are sequentially removed by the physicochemical treatment process by the superconducting magnetic separation device 5 and the biological treatment process by the vegetation 7, so that the eutrophic substance can be efficiently removed. Can be removed. And not only does it not be necessary to purify the entire closed water area 2 into which river water containing eutrophic substances has flowed in as in the prior art but to use it, but the nature that it originally has is restored in the second water purification area 6b. The possibility of being increased increases the hydrophilicity.
[0027]
With such a purification system configuration, it is possible to prevent at least a deterioration in the quality of water taken from the purification region 6. Furthermore, in the vegetation purification facility, the improvement of the water quality of the second water purification area 6b promotes the growth of aquatic plants that have conventionally inhabited the closed water area 2, and consequently the original second water purification area. A series of natural purification mechanisms will be restored in which the ecosystem of 6b is partially restored and water quality is further improved. Therefore, the progress of eutrophication is stopped also in the purification region 6 as a whole, and it becomes possible to improve to a useful water area such as water use and hydrophilic area.
[0028]
Here, even if the amount of river water increases in the rainy season or during flooding, the water taken by the superconducting magnetic separation device 5 is substantially isolated from the other areas of the closed water area 2 by the partition 10. Therefore, there is an advantage that the purification area 6 can be secured as a purified water area.
[0029]
The vegetation 7 shown in FIG. 2 is employed when the second water purification region 6b is shallow, and is configured by directly planting a plant such as a cocoon in soil in a shallow water region. The second partition body 14 shown in FIG. 2 rises from the bottom of the shallow region to form the second water purification region 6b.
[0030]
Further, when the water depth is deep and it is difficult to plant aquatic plants directly on the soil, as shown in FIG. 3, a plurality of floating islands 11 having a vegetation base 13 are floated and a vegetation base 13 is mounted. Plant aquatic plants to grow vegetation. This also provides a purification effect similar to that of the vegetation 7 shown in FIG.
[0031]
Here, the vegetation base 13 to be mounted on some floating islands 11 should preferably use the bottom mud of the closed water area 2 if possible. This is because if the water quality is improved, seeds in the soil may germinate and grow. In lakes and other areas where water is generally used, revetment work has been carried out, the water depth has become deeper, water quality has deteriorated, and aquatic plants can no longer grow properly. In such a case, the seeds of plants that can no longer live in the bottom mud may be dormant.
[0032]
By installing the vegetation base 13 including such seeds on the floating island 11 and adjusting the water level according to the growth environment, the seeds may germinate, and the partial recovery of the ecosystem of the closed water area 2 is achieved. Is possible. Such an example can be found in the literature (Environmental Resources, May 2002, Vol 38, No. 6, P83-P88 “River Water Purification Complex System Applying Superconducting Magnetic Filter and Vegetation”).
[0033]
As described above, since the first and second purification equipments 5 and 30 are arranged, the installation space for the purification equipment can be reduced. In particular, implementation in lakes near urban areas can be facilitated.
[0034]
Next, details of the partition 10 will be described with reference to FIGS. 2 and 4. The first partition 10 includes a plurality of partition plates 20, a weight 22 attached to the lower end of the partition plate 20 so as to be vertical in water, a plurality of floating members 23, and the partition plate 20 in water. It is connected to the partition plate 20 so as to be lined up and down and is provided with a floating member 23. The plurality of partition plates 20 are arranged so as to be lined up almost from the water surface to the lake bottom. The partition plate 20 floating member 23 is configured with buoyancy so that the plurality of partition plates 20 are held in water.
[0035]
The partition 10 partitions a part of the lake and is desirably installed along the lake shore which is not easily affected by the indirect lake water flow caused by the inflow of the river. This is to prevent the first partition 10 from being swept away or damaged by the water pressure when the amount of river inflow increases, such as during a flood. On the other hand, since various objects such as wood flow from the inflowing river 1, it is desirable to protect the outer periphery of the floating member 23 and the like with a metal net-like member (not shown) so as to withstand these.
[0036]
Next, the biological treatment facility 30 shown in FIG. 2 will be specifically described. The partition 14 in the second water purification region 6b provided in the purification region 6 is preferably a wooden pile or the like, taking advantage of the natural landscape, especially when the lake is shallow. In general, among buoyant and floating plants among aquatic plants (including water extractability, floatability, floatability, and subsidence plants), the resistance to high waves and rolling up of the bottom mud is weak. It is desirable to arrange the partition 14 so as not to directly receive the wave propagating on the lake surface and the water flow in the lake as much as possible. Waves can be extinguished by placing wooden stakes next to each other in parallel or by fixing a hodder tree (not shown) around the periphery.
[0037]
Next, the biological treatment facility 30 shown in FIG. 3 will be specifically described. In the case of the floating island 11, it is necessary to fix the floating island 11 firmly to the bottom of the lake with an anchor 15 or the like so that the floating island 11 is not washed away by the water current in the lake or greatly shaken by the waves. As a mooring method, you may fix to a shore with a mooring rope (not shown). Moreover, the water level in the floating island 11 needs to be devised so as to make the water surface in the floating island 11 constant by providing a water access pipe 16 so that the water level communicates with the outside water. When these plants grow on floating islands 11 are vegetated for the purpose of removing nitrogen, it is necessary to maintain them so that they are harvested in the fall and winter when they die and are taken out of the lake and processed. If it does in this way, it is thought that the living space (biotope) of a living body can be gradually formed in the biological treatment facility 30 and its storage water area 6.
[0038]
Next, the superconducting magnetic separation device 5 that separates and removes contaminants such as phosphate will be described. The superconducting magnetic separation device 5 is compact because it saves energy and can be purified at high speed. Therefore, it can generally be installed in a narrow space near the mouth of the inflowing river. Since it can be installed near the water intake point, the distance between the water intake point and the device is shortened, and there is an advantage that the water intake power that occupies a large power consumption in the purification device can be reduced.
[0039]
Hereinafter, the function of the superconducting magnetic separation device will be described with reference to FIGS.
[0040]
FIG. 5 shows a magnetic separation apparatus in which air-core solenoid magnets are arranged vertically and a rotary filter is arranged close to the upper end, and a matrix group 101 made of a ferromagnetic material is attached and a central axis 102 is taken as an axis. The disk-type rotary filter 103 that can be continuously processed by rotating is a longitudinal cross-sectional structure diagram of a magnetic separation device that is disposed on the upper extension of the air core shaft of the liquid helium cooled superconducting magnet 105 housed in the vacuum heat insulating container 104. is there. FIG. 6 is a horizontal sectional view taken along the line BB in FIG. It shows that the donut-shaped matrix group 101 is mounted on the disk-type rotary filter 103. The disk-type rotary filter 103 is disposed on the upper side of the superconducting magnet 105. By balancing the magnetic attraction support force of the matrix group 101 by the superconducting magnet 105 with the weight of the superconducting magnet 105, the supporting force applied to the support structure (not shown) of the superconducting magnet 105 provided in the vacuum heat insulating container 104 can be reduced. Therefore, the support structure of the superconducting magnet 105 in the vacuum heat insulating container 104 is simplified, and the initial cost of the superconducting magnet 105 can be reduced. The superconducting magnet 105 can generate a high magnetic field equal to or higher than the saturation magnetic flux density of the magnetic powder in the matrix group 101 of the disk-type rotary filter 103 disposed on the upper extension of the air core axis. By using a network structure magnetic material that can secure a high gradient magnetic field, magnetic separation is possible even with a low concentration (for example, 5 to 10% of the concentration of water sludge to be treated) of magnetic powder injection, so that the running cost can be reduced. Further, although not shown, a power source and a permanent current switch are connected to the superconducting magnet 105, and the running cost can be reduced by the operation in the permanent current mode.
[0041]
The magnetic separation operation of this embodiment is as follows. The treated water 106 including the magnetic aggregates generated in the pretreatment flows into the water pipe 110 passing through the bore of the superconducting magnet 105 from the lower side 107 and flows upward, and is disposed on the upper extension of the air core shaft. When passing through the matrix group 101 attached to the disk-type magnetic filter 103, the magnetic aggregates in the treated water 106 are adsorbed by the matrix group 101, and the purified water flows out from the purified water outlet 108. The disk-type rotary filter 103 equipped with the matrix group 101 that adsorbs the magnetic aggregates receives the driving force of the electric motor 109 connected to the power source and rotates around the central axis 102, and adsorbs the magnetic aggregates on the water pipe 110 side. The matrix group 101 rotates and moves to the cleaning unit on the side opposite to the water pipe 110 side. In the cleaning unit, particles of particles such as magnetic aggregates attached to the matrix group 101 are peeled off by spraying purified water from the sprinkling space 111 disposed above the disk-type rotary filter 103. The magnetic field strength of the cleaning unit is reduced by the iron shield 112 provided on the outer periphery of the vacuum heat insulating container 104, and particles such as magnetic aggregates attached to the matrix group 101 can be easily separated. The matrix group 101 has a structure in which a reticulated magnetic stainless steel is laminated vertically, horizontally, obliquely, concentrically, or any combination thereof, so that a high gradient magnetic field can be secured, and the generated magnetic field of the superconducting magnet 105 is used as the superconducting magnet 105. By setting the magnetic field to be equal to or higher than the saturation magnetic flux density (about 0.5 T) of the magnetic powder at 101 parts of the matrix group disposed on the air axis extension, a high gradient magnetic separation device can be provided. The particles separated from the matrix group 101 in the washing section are collected in a mud collection container 113 below the washing section, and flow down to the concentrating tank 115 through the mud pipe 114, where the sludge 115 concentrated and settled is the sludge extraction port 116. Can be pulled out from. By disposing the magnetic separation matrix group 101 in the upper part of the vacuum heat insulating container 104 in this way, the mud collection container 113 and the concentration tank 115 can be disposed substantially parallel to the vacuum heat insulating container 104, so that the disk-type magnetic filter 103 is replaced with a superconducting magnet. Compared with the case where it is arranged below 105, since the height of the concentration tank 115 can be increased without increasing the height of the entire apparatus, the sludge concentration can be further increased. The supernatant water from which the particles have settled and separated can be taken out from the overflow outlet 117 of the concentrating tank 115, and the amount of flow from the mud collection container 113 to the concentrating tank 115 is adjusted from the overflow adjusting valve 118 and the sludge extraction port 116. Adjustment is possible by adjusting the pull-out amount. In this case, the amount of flow from the mud collecting container 113 to the concentrating tank 115 is the amount of discharge adjusted by the flow rate adjusting valve 124 provided in the middle of the discharge piping of the water injection pump 125 and the amount of extraction from the sludge extraction port 116. Almost determined by adjustment. The supernatant water of the sludge concentration tank 115 is returned from the pipe 117 to the raw water tank (not shown in the figure) through the flow rate adjustment valve 118. A check valve 119 is installed on the upstream side of the sprinkling pipe 111 to prevent backflow. Further, the inclination angle of the side wall of the mud collection container 113 is larger than the repose angle of the particles that settle, so that the particle group does not accumulate in the mud collection container 113 but sinks into the concentration tank 115. In addition, the thickening tank 115 can take the sludge concentrated by gravity from the sludge extraction port 116 by taking an angle larger than the repose angle of the concentrated particles. The rotary filter 103 is stored in a fixed filter case 120, and watertightness to the outside is maintained by a partition wall. The rotary filter 103 can be rotated continuously or intermittently by the driving force of the electric motor 109 that can change the speed around the central shaft 102, and the portion where the central shaft 102 penetrates the filter case 120 has a structure that does not leak water by the shaft sealing mechanism. Yes. The electric motor 109 may be disposed at a distance from the superconducting magnet 105, and the magnetic filter may be driven via a chain, a belt, a shaft, or the like. The vacuum insulation container is provided with an inlet 122 for injecting liquid helium via a gate valve 121 and a helium gas safety valve 123. When the superconducting magnet 105 is quenched, the helium gas is connected to the safety valve 123. It is discharged to a safe place through the conduit. The arrangement order of the sprinkling amount adjusting valve 124 and the check valve 119 is not adversely affected even if it is reverse to the present embodiment. According to the present embodiment, not only the structure of the magnetic separation device is simplified, but also the amount of magnetic powder injection can be greatly reduced by the filter structure capable of maintaining a high magnetic field and a high gradient magnetic field, and further, washing Since the peeled magnetic aggregates are reduced in volume by concentration, post-treatment facilities such as magnetic powder recovery processing and sludge dehydration can be reduced in size, so that initial costs and running costs can be reduced.
[0042]
FIG. 7 is a flowchart of the embodiment of the magnetic separation system including FIG. 5 and FIG. 6 and magnetic powder recovery and reuse. Roughly speaking, water intake means, water supply means, additive injection means, floc forming means, magnetic separation means, purification It consists of water discharge means, magnetic powder recovery and reuse means, and sludge dewatering means. The raw water containing pollutants such as phosphate and blue seawater is taken from the lake and the like by the water intake means and sent to the magnetic separation means by the water supply means. In the water supply path to the magnetic separation means, the additive injection means injects an additive necessary for generating the magnetic aggregate, and the floc forming means generates the magnetic aggregate that is an aggregate of magnetic powder and contaminants. . When the pollutant is soluble inorganic phosphoric acid, it chemically reacts with the agglomeration additive to produce an insoluble metal salt, and aggregates are produced. In the magnetic separation means, the magnetic aggregates are separated and concentrated from the water to be treated containing the magnetic aggregates, and the purified water is recycled or reused as purified water by the purified water discharge means. The concentrated magnetic agglomerates are separated into magnetic powder and contaminated sludge by magnetic powder recovery and reuse means, and the magnetic powder is reused. Sludge is dewatered by sludge dewatering means to become dewatered sludge.
[0043]
The water intake means is composed of a screen 128, a water intake tank 129, a water intake pump 130, etc., and raw water 131 containing contaminants such as phosphates and solid suspended solids passes through the screen 128 and flows down to the water intake tank 129. Water is taken in by a water intake pump 130 installed in the water tank 129 and sent to the raw water tank 132. On the screen 128, coarse dust floating in the raw water is removed in advance, and the removed dust is discarded. The intake pump 130 is a submersible pump and is controlled in conjunction with water level meters provided in the intake tank 129 and the raw water tank 132, respectively. Reference numeral 133 denotes a water supply pipe, which is connected to the raw water tank 132 from the discharge port of the water intake pump 130, and a gate valve and a check valve are connected therebetween.
[0044]
The water supply means includes a raw water tank 132, a raw water stirrer 134, a water supply pump 136, a water supply pipe 136, and the like. The raw water tank 132 supplies the raw water taken by the water intake means and the supernatant water and sludge dewatered in the concentration tank 115 described in FIG. Water to be treated such as separated water of the means flows in, and the raw water agitator 134 makes it possible to make the concentration of contaminants uniform and to prevent sedimentation of contaminants. The water to be treated is drawn from the raw water tank 132 by the water pump 135 connected to the raw water tank 132 by a conduit, passes through the water supply pipe 136 connected to the discharge port of the water pump 135, and passes through the additive injection means and the flock forming means. Sent to the magnetic separation means. A flow rate adjustment valve 137, a check valve 138, a flow meter 139, a turbidity meter 140, and a pressure gauge 141 are connected to the water supply pipe 136. Further, the water supply pipe is branched in the middle, and a part of the water to be treated is returned to the raw water tank 132 to adjust the amount of water supply and to stir the raw water tank 132. The treated water is returned to the raw water tank 132 through the return pipe 143. A check valve is provided in the middle of the return pipe to prevent backflow. The water pump 135 is interlocked with a water level meter provided in the raw water tank 132, and when the water level of the raw water tank 132 is abnormally lowered, the water pump 135 is stopped to prevent an accident such as a failure of the water pump 135.
[0045]
The additive injection means includes magnetic powder injection means, inorganic flocculant injection means, pH adjuster injection means, and polymer flocculant injection means. The magnetic powder injection means includes a magnetic powder hopper 144, a magnetic powder feeder 145, a diluted water injection pipe 146, and a magnetic powder slurry agitator 147. The magnetic powder is stored in the magnetic powder hopper 144, and the magnetic powder hopper 144 A magnetic powder feeder 145 provided at the bottom of the hopper 144 is put into the magnetic powder dilution tank 148. The diluted water is injected from the purified water tank 149 through the diluted water injection pipe 146 by the purified water pump 150 into the magnetic powder dilution tank 148 and mixed with the magnetic powder by the magnetic powder slurry agitator 147 provided in the magnetic powder dilution tank 148. Thus, the magnetic powder slurry is replenished. The magnetic powder hopper 144 is connected to a magnetic powder input port 151 and a recovered magnetic powder input means 152 so that the magnetic powder is replenished. The magnetic powder feeder 145 is linked to a water level meter and an input amount integrating meter 153 provided in the magnetic powder dilution tank 148. When the liquid level of the magnetic powder dilution tank 148 is lowered to a predetermined position, the operation is started and the input amount is integrated. The operation is stopped when a predetermined amount is accumulated in total 153. An integrating flow meter 145 and an electromagnetic valve 155 are connected to the dilution water injection pipe 146, and the electromagnetic valve 155 is linked to the water level meter and the integrating flow meter 154 of the magnetic powder dilution tank 148, and the liquid level of the magnetic powder dilution tank 148. When the water level drops to a predetermined position, it opens and water injection starts, and when a predetermined flow rate is integrated by the integrated flow meter 154, it closes and water injection stops. In addition, the magnetic powder slurry injection pump 156 is linked to the water level gauge of the magnetic powder dilution tank 148, and stops when the liquid level of the magnetic powder dilution tank 148 is abnormally lowered, causing an accident such as failure of the magnetic powder slurry injection pump 156. Is prevented in advance. Although not shown, the magnetic powder hopper 144 is provided with an arch breaker to send dry air. As the magnetic powder feeder 145, a screw feeder or a table feeder is used.
[0046]
The inorganic flocculant injection means is means for injecting the inorganic flocculant stored in the inorganic flocculant storage tank 157 into the water supply pipe 136 through the inorganic flocculant injection pump 158 and the inorganic flocculant injection pipe 159. The inorganic flocculant storage tank 157 is provided with an inorganic flocculant stirrer 160, so that the inorganic flocculant concentration in the inorganic flocculant storage tank 157 is made uniform and deposition is prevented. The inorganic flocculant injection pump 158 is a positive displacement metering pump, interlocked with a water level meter provided in the inorganic flocculant storage tank 157, and stops when the liquid level of the inorganic flocculant storage tank 157 is abnormally lowered. Accidents such as failure of the flocculant injection pump 157 are prevented in advance. Further, an inorganic flocculant injection amount adjusting function is added to the magnetic powder injection amount control means and connected to the inorganic flocculant injection pump 158 to control the inorganic flocculant injection amount in accordance with the amount of contaminants in the water to be treated. Is also possible. As the inorganic flocculant, vane sulfate earth or iron-based inorganic flocculant is used, and the inorganic flocculant storage tank 157 is replenished from the replenishment port 161. The inorganic flocculant injection pipe 159 is connected to the water supply pipe 136 via a check valve.
[0047]
The pH adjusting agent injection means is suitable for coagulating the pH of the water to be treated by injecting the pH adjusting agent stored in the pH adjusting agent storage tank 162 into the water supply pipe 136 with the pH adjusting agent injection pump 163 and the pH adjusting agent injection pipe 164. It is means to adjust to the value. The pH adjusting agent storage tank 162 is provided with a pH adjusting agent stirrer 165 to achieve uniform concentration of the pH adjusting agent in the pH adjusting agent storage tank 162 and prevention of deposition. The pH adjusting agent injection pump 162 is a positive displacement metering pump, interlocked with a water level meter provided in the pH adjusting agent storage tank 162, and stops when the liquid level in the pH adjusting agent storage tank 162 is abnormally lowered. Accidents such as failure of the adjusting agent injection pump 163 are prevented in advance. Further, the pH of the water to be treated can be controlled by controlling the discharge amount of the pH adjusting agent injection pump using a pH meter and a pH controller. A sodium hydroxide solution or a calcium hydroxide solution is used as the pH adjusting agent, and the pH adjusting agent storage tank 162 is replenished from the replenishing port 166. The pH adjusting agent injection pipe 164 is connected to the water supply pipe 136 via a check valve.
[0048]
The polymer flocculant injection means includes a polymer flocculant hopper 167, an input accumulator 168, a polymer flocculant feeder 169, polymer flocculant dissolution tanks 170 and 171, polymer flocculant agitators 172 and 173, polymer flocculant It is composed of infusion pumps 174, 175 and the like. The polymer flocculant is stored in the polymer flocculant hopper 83, and the polymer flocculant dissolution tank 170 is fed from the polymer flocculant hopper 167 to the polymer flocculant feeder 169 provided below the polymer flocculant hopper 167. Alternatively, the diluted water is poured into the polymer flocculant dissolution tank 170 or 171 from the purified water tank 149 through the diluted water injection pipe 176 or 177 by the purified water pump 150. In the polymer flocculant dissolution tank 170 or 171, the polymer flocculant is dissolved in the dilution water by the polymer flocculant stirrer 172 or 173. Since dissolution of the polymer flocculant takes about 1 hour, dissolution and storage are alternately performed in the polymer flocculant dissolution tanks 170 and 171, and the capacity of each tank is set to be more than the capacity used for 1 hour. From the stored polymer flocculant dissolution tank, the water is injected into the water feed pipe 136 or the sludge dewatering means by the polymer flocculant injection pumps 174 and 175 and the polymer flocculant injection pipes 176 and 177. The polymer flocculant hopper 167 is replenished with the polymer flocculant from the polymer flocculant inlet 178. The polymer flocculant feeder 169 is interlocked with a water level meter provided in the polymer flocculant dissolution tank 170 or 171 and an input amount integrating meter 168, and the liquid level of the polymer flocculant dissolution tank 170 or 171 reaches a predetermined position. When it drops, the charging is started, and when a predetermined amount is integrated by the charging amount integrating meter 168, the charging is stopped. Further, the polymer flocculant feeder 169 has a mechanism for switching the charging destination, and can switch the charging destination to the polymer flocculant dissolution tank 170 or 171. Although not shown, the polymer flocculant hopper 167 is provided with an arch breaker to send dry air, and a screw feeder or a table feeder is used for the polymer flocculant hopper 167. An integrated flow meter 179 and an electromagnetic valve 225 are connected to the dilution water injection pipe. The electromagnetic valve 225 is linked to the water level meter and the integrated flow meter 179 of the polymer flocculant dissolution tank 170 or 171 to dissolve the polymer flocculant. When the liquid level in the tank 170 or 171 drops to a predetermined position, it opens and water injection is started, and when a predetermined flow rate is integrated by the integrated flow meter 179, it closes and water injection is stopped. Further, the dilution water injection pipe branches into a dilution water injection pipe 176 and a dilution water injection pipe 177, and is polymerized via an electromagnetic valve 180 or 181 that opens and closes in conjunction with the water level gauge of the polymer flocculant dissolution tank 170 or 171. Connected to the flocculant dissolution tank 170 or 171, the solenoid valve 180 or 181 is opened when the liquid level drops to a predetermined low water level and diluted water is injected, and when the liquid level rises to a predetermined high water level, it is closed and diluted. Water injection is stopped. The polymer flocculant injection pumps 174 and 175 are positive displacement metering pumps, interlocked with the water level gauge of the polymer flocculant dissolution tank 170 or 171, and the liquid level of the polymer flocculant dissolution tank 170 or 171 decreases abnormally. When this happens, it stops and accidents such as failure of the polymer flocculant injection pumps 174 and 175 are prevented. The suction ports of the polymer flocculant injection pumps 174 and 175 are connected in parallel to the polymer flocculant dissolution tanks 170 and 171, and the polymer flocculant dissolution tank in which storage is performed by switching the valves 182 and 183. And the polymer flocculant can be extracted. As the valves 182 and 183, electromagnetic valves, electric valves or the like are used, and opening / closing control is possible by interlocking with the water level gauges of the polymer flocculant dissolution tanks 170 and 171. A check valve is connected in the middle of the pipes of the polymer flocculant injection pipes 176 and 177 to prevent backflow.
[0049]
The floc forming means is composed of a rapid stirrer 184 and a slow stirrer 185 to which a water supply pipe 136 is connected, and a polymer flocculant injection pipe 176 is connected to a conduit connected to the quick stirrer 184 and the slow stirrer 185. A polymer flocculant is injected. The water to be treated into which the additive has been injected by the additive injection means is sent to the rapid stirrer through the water pipe 136, and the additive and contaminants (for example, solid suspended matters, phosphates, soluble heavy metals, E. coli, etc.) Are uniformly dispersed in the water to be treated to produce micro flocs, and then a polymer flocculant is injected into the water to be treated and magnetic aggregates are formed by a slow agitator. A static mixer with no moving parts is used for the rapid stirrer, and a sealed agitation tank and a stirrer with a predetermined capacity are used for the slow agitator. However, a static mixer or a pipe-type stirrer may be used for both. Is possible.
[0050]
The magnetic separation means is based on the magnetic separation apparatus described with reference to FIGS. 5 and 6, and the water to be treated containing magnetic aggregates is magnetically separated by a conduit 186 connected from the slow agitator 185 to the water conduit 110 of the magnetic separation unit. After being sent to the apparatus and magnetic agglomerates being magnetically separated, the purified water is sent to the purified water tank 149 through the conduit 187. Washing water used in the magnetic separation device is sent from the pressurizing pump 188 to the sprinkler pipe 111, and a check valve 119, a flow rate adjusting valve 124, and a flow meter 126 are provided in the wash water pipe. The supernatant water taken out from the concentration tank 115 of the magnetic separator is sent to the separation water tank 189 from the concentration tank upper supernatant water outlet by a conduit 190 connected to the separation water tank 189, and to the supernatant water outlet side of the conduit 190. Is provided with a flow meter 191 and a regulating valve 118 to adjust the amount of supernatant water taken out. The sludge concentrated and reduced in the concentration tank 115 is sent to the magnetic powder recovery and reuse means. Helium gas from the safety valve of the vacuum insulation container of the magnetic separation apparatus is discharged to the atmosphere from a safe discharge port 193 through a conduit 192 connected to the safety valve.
[0051]
Purified water is mainly used as cleaning water for the disk-type rotary filter 103 as well as diluting water for magnetic powder and coagulant, mainly by discharging the purified water obtained by the magnetic separation means to a lake or the like. Since part of the purified water is used as dilution water, it is once stored in the purified water tank 149 and discharged by the purified water pump 150 and the discharge pipe 194. The discharge pipe 194 is branched into the dilution water feed pipe 195 in the middle of the pipe, and a part of the purified water is used as the dilution water for the additive injection means. When the purified water tank 149 is empty or the amount of water is small, such as before the start of the purification operation, the cleaning water and dilution of the disk-type rotary filter 103 at the start of the operation are performed by replenishing the purified water tank 149 with a necessary amount of tap water. Water is secured. The tap water is connected to the tap water connection port 196 and injected into the purified water tank 149 through a valve. Regulating valves 197 and 198 are connected to the discharge pipe 194 and the dilution water transfer pipe 195, respectively, and the purified water distribution pressure from the discharge pipe 194 to the dilution water transfer pipe 195 can be adjusted. Prevention is intended. In addition, a pressure gauge 199 is provided in a pipe line between the purified water pump 150 and the diluting water transfer pipe 195 branch point, and the discharge pressure can be monitored. The purified water pump 150 is interlocked with a water level gauge provided in the purified water tank 149, and when the liquid level in the purified water tank 149 is abnormally lowered, the purified water pump 149 is stopped to prevent an accident such as a failure of the purified water pump 150. The In addition, when the purified water discharge destination is lower than the purified water tank 149 and the purified water pump 150 is not required for discharge, the purified water pump 150 is used only for diluting water supply, and the discharge from the purified water tank 149 is used. If the overflow is caused to flow down to the discharge destination through the conduit, the purified water pump 150 can be reduced in size, and if the purified water pump 150 is not required for diluting water supply, the purified water pump 150 is unnecessary and the device is It can be simplified. The washing water for the disk-type rotary filter 103 is also sent from the purified water tank by the washing water pressurizing pump. A cleaning flow meter 126, a flow rate adjustment valve 124, and a check valve 119 are arranged in the middle of the cleaning water pipe to prevent adjustment of the cleaning flow rate and backflow from the magnetic separation body.
[0052]
In the magnetic powder recovery and reuse means, the sludge of the magnetic aggregate drawn from the lower part of the concentration tank of the magnetic separation means is ground by the grinder 200 and decomposed with high purity into the sludge and the magnetic powder, and then the sludge pump 201, sludge The sludge sent to the magnetic separator 203 by the transfer pipe 202 and passed through the magnetic separator 203 flows down the conduit 204 and enters the sludge tank 205, and the magnetic powder recovered by the magnetic separator 203 passes through the recovered magnetic powder input means 152. The magnetic powder popper 144 is replenished and reused. A homomixer is used for the attritor 200, and a part of sludge can be continuously circulated by the conduit 206 bypassing the inlet and the outlet and the valve 207 in the conduit, so that the decomposition purity can be increased. Further, in this example, the sludge pump 201 is installed at the subsequent stage of the attritor 200, but the attritor 201 may be installed at the subsequent stage of the sludge pump 201. The amount of sludge sent from the concentration tank 115 to the magnetic separator 203 via the attritor 200 and the sludge pump 201 is adjusted by a valve provided on the sludge transfer pipe 202. The magnetic separator 203 includes a motor-driven rotating disk in which permanent magnets are embedded, a separation tank in which grinding sludge enters, and a scraper that scrapes off magnetic powder adsorbed by the permanent magnets of the disk, and a part of the rotating disk is a separation tank. The magnetic powder is adsorbed by the permanent magnet of the rotating disk until the sludge entered the separation tank rotates and flows into the overflow side on the opposite side and overflows. The powder moves into the air as the rotating disk rotates, and is scraped off and collected by a scraper. Further, stirring blades are provided on the outer periphery of the rotating disk and the inner wall of the separation tank, and sludge in the separation tank is agitated by the rotation of the rotating disk to prevent magnetic powder from being deposited. For example, a screw feeder or a belt conveyor can be used as the recovered magnetic powder input means 152. However, the magnetic separator 203 is disposed directly above the magnetic powder input port of the magnetic powder hopper 65, and the recovered magnetic powder is By dropping the magnetic powder into the magnetic powder hopper 144, the recovered magnetic powder input means 152 becomes unnecessary and the apparatus can be further simplified. Further, the magnetic separator 203 may be disposed just above the magnetic powder dilution tank 148 so that the recovered magnetic powder is dropped into the magnetic powder dilution tank 148 by gravity drop, and the recovered magnetic powder input means 152 is omitted. And the device can be simplified.
[0053]
The sludge dewatering means is a means for dewatering and reducing the volume of sludge by the sludge dewatering machine 208, and for making sludge transportation easy. The sludge is discharged from the sludge tank 205 by the sludge supply pump 209 and the supply pipe 210. To be supplied. The sludge dehydrator 208 is connected with a polymer flocculant injection pipe 177 from the additive injection means to inject the polymer flocculant, and the dewatered sludge is dropped into the shooter 211 from the sludge discharge port and is fed by the sludge feeder 212. The separated water is transferred to the sludge recovery container 213, and the separated water flows down from the separated water discharge port to the separated water tank 189 through the conduit 214 and is separated into the raw water tank 132 by the separated water pump 215 and the conduit 189 together with the supernatant water of the concentration tank of the magnetic separation means. Sent. The sludge supply pump 209 is a submersible slurry pump with a fritted switch. When the sludge liquid level in the sludge tank 205 is abnormally lowered, the sludge supply pump 209 is stopped to prevent an accident such as a failure of the sludge supply pump 209. Further, the separated water pump 215 is a submersible pump with a fritted switch, and stops when the water level of the separated water tank 209 is abnormally lowered to prevent an accident such as a failure of the separated water pump 215. A slurry flow meter 216 and a flow rate adjustment valve 217 are provided in the middle of the supply pipe 210. Further, a flow meter 218, a valve 219, and a check valve are connected in the middle of the conduit 216. The dewatered sludge 220 stored in the sludge collection container 213 can be transported and disposed of, for example, a waste disposal site, or can be recycled as a compost raw material. In particular, in facilities that do not collect and reuse magnetic iron powder, the iron content in the sludge increases, so that it can be recycled as a raw material for cement that requires iron.
[0054]
In addition, all the tanks used in the present embodiment are provided with a level gauge, an overflow pipe, and a drain pipe, and all the overflow and drain are collected in a drainage groove and drained into, for example, sewage. Moreover, it is also possible to use a tank made of reinforced concrete for the tanks used in this embodiment. Although the control panel is omitted in the figure, all the devices and devices constituting this embodiment are supplied with power from the control panel, and are operated and sequence controlled. Here, the power of this facility may use a normal commercial power source, and specially for this facility, power generation facilities such as wind power generation, solar power generation, biomass power generation, fuel cell power generation facilities are installed. These can be supplied alone or in combination. According to the present embodiment, space saving and energy saving are achieved by simplifying the operation of the operator at low cost by simplifying the structure of the magnetic separator, reducing the concentration of magnetic powder injection, and collecting and reusing the magnetic powder. -A magnetic separation device can be provided, and is suitable for purifying phosphorus and suspended solids in closed water areas such as lakes.
[0055]
Next, the vegetation equipment for removing nitrogen, which is the second purification step, is as follows. Two vegetation facilities for cultivating aquatic plants can be expected: water purification effects such as nitrogen removal by plants, and creation of ecosystems. The organic nitrogen in the treated water from which phosphorus and other substances have been separated and removed in the first purification process is decomposed by microorganisms adhering to the plant and converted to ammonia and inorganic salts such as nitrite and nitrate nitrogen. Is done. Since plants grow using solar energy while absorbing these inorganic salts, nitrogen components are taken into the plant body and removed from the water area. In addition, organisms attached to the surface of the plant also play an important role in decomposing organic substances and removing nutrients.
[0056]
Table 1 shows an example of measuring the removal rate of plants with respect to nitrogen and phosphorus as eutrophication substances in the water purification test of each plant.
[0057]
[Table 1]

In the superconducting magnetic separation apparatus 5 used in the first purification process for removing phosphorus and the like, the installation space is that of an apparatus having a treated water volume of 5000 m 3 / day (corresponding to a water supply amount of about 20,000 people). In this case, the installation space is about 300m ² Thus, a phosphorus removal rate of 85% or more can be obtained. On the other hand, when removing nitrogen in the vegetation purification facility 7 which is the second purification process, the vegetation area necessary for purifying the water volume of 5000 m3 / day is 10 ppm in the case of reeds. Approximately 500,000m ² It is a calculation that can remove 67% of nitrogen in the reed field. This required area is an order of magnitude larger than that of the first phosphorus purification process.
[0058]
However, even if this vegetation area cannot be secured, the removal of one phosphorus of the eutrophic salt provides a more favorable environment for the growth of plants that were unable to grow and reproduce. And it becomes possible to grow using residual phosphorus as a nutrient source. This is because it has been found that algae such as blue-green algae can be prevented from breeding even if certain conditions such as nutrient salts, light, water temperature, carbon dioxide gas, and water circulation are lacking.
[0059]
Therefore, in reality, it is difficult to separate and remove nitrogen for the entire amount of treated water of the phosphorus removal device due to the limitation of the installation space of the vegetation 7, but about a part of the treated water of the superconducting magnetic separation device 5 Even if it is purified by vegetation 7, it is possible to achieve part of the purpose. For this reason, the second purification step may be bypassed for most of the treated water from which the contaminants have been separated and removed in the first purification step. The bird's-eye view of FIG. 1 shows such an example, the partition body 14 is disposed so as to surround the second water purification region 6b in which the second purification step is performed, and the second water purification region 6b in the second purification step. It is designed to allow the stored water to flow around the offshore side of the river.
[0060]
Here, there is no problem even if water is mixed in the first water purification area 6a of the bypass channel and the second water purification area 6b of the vegetation zone, and the water flow propagated through the purification area 6 partitioned from the lake 2 Or the partition 14 of the grade which can prevent a wave is enough. Moreover, in the purification area | region 6, it is sufficient if it can suppress to some extent that water mixes with the partition body 10 with the lake water outside it. Conversely, by allowing the partition body 10 to enter and leave a small amount of water, the external force applied to the partition body 10 due to the river flow or the blowing flow is alleviated, and the partition body 10 can be prevented from flowing out.
[0061]
In addition, for example, in the case of a tap water source, even if the amount of water intake at night is reduced, if the operation of the superconducting magnetic separation device 5 is continued, the amount of stored water in the purification region 6 increases, Out of the lake 2 and contribute to purification as dilution water of the lake. Furthermore, it is more effective to carry out not only purification of river water but also removal of dredged sediment from the lake. This is because the eutrophic lake is in an anoxic state near the bottom, and the accumulated phosphorus and nitrogen are eluted from the bottom mud and further added to the nutrient load.
[0062]
In addition, in the first purification step, a coagulation precipitation filtration method can be applied. This is because phosphate and suspended solids can be removed by this method.
[0063]
According to the present embodiment, a part of water flowing from a river or the like into a closed water area 2 such as a lake is taken, and this water is physicochemically processed to mainly remove phosphorus, The treated water treated in the first purification step is introduced into the purification region 6 formed by partitioning the closed water region 2 in the depth direction, and the treated water is biologically treated in the purification region 6 to mainly generate nitrogen. Since it consists of the 2nd purification process to remove, the eutrophication by the pollutants such as phosphorus and nitrogen in the purification area 6 such as lakes and marshes is suppressed, and a water source for high-quality water is obtained and the hydrophilicity of the purification area 6 And restore the original ecosystem.
[0064]
Furthermore, since the physicochemical treatment is performed using the superconducting magnetic separation device 5, high-speed and high-efficiency phosphorus separation / removal can be performed, thereby achieving a significant space saving and energy saving in water purification.
[0065]
Furthermore, since biological treatment using vegetation is performed, it is possible to restore the original ecosystem while improving the landscape of the purification region 6 constituting a specific portion in the closed region 2.
[0066]
In addition, a part of water flowing from a river or the like into a closed water area 2 such as a lake and the like, and a superconducting magnetic separation process to remove mainly phosphorus, and a closed water area 2 The treated water treated in the first purification step is diverted into the first purification region 6a and the second purification region 6b formed by partitioning the water in the depth direction and introduced into the second purification region 6b. Since the introduced treated water consists of a second purification step in which the treated water is biologically treated in the second purification region 6b to mainly remove nitrogen, the water quality improvement of the closed water area 6 having a relatively large amount of stored water is more effective. Can be carried out reliably.
[0067]
Further, since the first purification region 6a is provided so as to be adjacent to and surround the second purification region 6b, the treated water in the first and second purification regions 6a and 6b flows out and mixes. Even if this is the case, the treated water is mixed and the first purification region 6a is not contaminated, and the predetermined purification performance in the second purification region 6b can be ensured.
[0068]
【The invention's effect】
According to the present invention, a purification method for lakes and the like that can suppress eutrophication due to contaminants such as phosphorus and nitrogen in a purification region such as lakes and marshes while minimizing facility costs, installation space, and drive energy. And a purification system thereof.
[0069]
Moreover, according to this invention, the purification method and its purification system of lakes etc. which can perform the water quality improvement of the closed water area with comparatively big stored water amount more effectively and reliably can be obtained.
[Brief description of the drawings]
FIG. 1 is a plan view of a peripheral portion to which a purification system such as a lake is applied according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view taken along the line AA of FIG.
3 is a cross-sectional view corresponding to AA in FIG. 1 of an application example different from FIG. 2;
4 is a side view showing a part of a partition body in the purification system of FIG. 1; FIG.
FIG. 5 is a configuration diagram of a magnetic separation unit of a superconducting magnetic separation device in the purification system of FIG. 1;
6 is a cross-sectional view showing a magnetic separation medium of the superconducting magnetic separation device of FIG.
7 is a flowchart showing a system configuration of a superconducting magnetic separation device in the purification system of FIG. 1; FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Inflow river, 1a ... River water intake, 2 ... Closed water area (lake etc.), 3 ... Lake shore, 4 ... Outflow river, 4a ... Overflow cough, 5 ... Superconducting magnetic separation device (physicochemical processing equipment) ) 5a ... first treated water discharge port, 6 ... purification region, 6a ... first purification region, 6b ... second purification region, 7 ... vegetation, 8 ... first purification process water region, 9 ... water intake intake, DESCRIPTION OF SYMBOLS 10 ... 1st partition body, 11 ... Floating island, 12 ... Floating island float, 13 ... Floating island soil, 14 ... Second partition body, 15 ... Floating island anchor, 16 ... Floating island water level adjustment communication pipe, 20 ... Partition Plate, 21 ... chain, 22 ... weight, 23 ... floating member, 30 ... biological treatment equipment.

Claims (9)

A first purification step in which a part of water flowing from a river or the like is taken into a closed water area such as a lake, and this water is physicochemically processed to mainly remove phosphorus;
The treated water treated in the first purification step is introduced into a purification region formed by partitioning the closed water area in the depth direction, and the treated water is biologically treated in the purification region to mainly remove nitrogen. A purification method for lakes and marshes characterized by comprising a second purification step. The method for purifying lakes and marshes according to claim 1, wherein the physicochemical treatment is performed using a superconducting magnetic separator. The method for purifying lakes and marshes according to claim 1 or 2, wherein the biological treatment is biological treatment using vegetation. A first purification step of taking a part of water flowing from a river into a closed water area such as a lake, and superconducting magnetic separation treatment to remove mainly phosphorus;
The treated water treated in the first purification step is diverted into the first purification region and the second purification region formed by partitioning the closed water region in the depth direction, and each is introduced to the second purification region. A purification method for lakes and marshes, etc., comprising a second purification step in which treated water introduced into the purification region is biologically treated in the purification region to mainly remove nitrogen. The method for purifying lakes and the like according to claim 4, wherein the first purification region is provided so as to be adjacent to and surround the second purification region. A physicochemical treatment facility that mainly removes phosphorus by taking a part of water flowing from rivers into closed water areas such as lakes,
A biological treatment facility that is formed by partitioning the closed water area in the depth direction and disposed in a purification area for introducing treated water treated by the physicochemical treatment apparatus, and mainly removing nitrogen. A purification system for lakes and other features. The purification system for lakes and marshes according to claim 6, wherein the physicochemical treatment facility is a superconducting magnetic separator. The purification system for lakes and marshes according to claim 6, wherein the biological treatment facility is a biological treatment facility using vegetation. A superconducting magnetic separation device that mainly removes phosphorus by taking a part of water flowing from rivers into closed water areas such as lakes,
Nitrogen is mainly disposed in one purification region of a plurality of purification regions formed by partitioning a closed water region in the depth direction and diverting the treated water treated by the superconducting magnetic separation device and introducing each of the treated water. A purification system for lakes and marshes characterized by a biological treatment facility that removes water.

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